Mutagenic properties of linuron and chlorbromuron evaluated by means of cytogenetic biomarkers in mammalian cell lines

Agricultural practices are usually supported by several chemical substances, such as herbicides. Linuron and chlorbromuron are phenylurea herbicides largely used to protect crops from weeds, blocking photosynthesis by inhibition of the photosystem II complex. The former, also commercially known as lorox or afalon, is selectively used to protect bean and French bean plants, fennels, and celeriacs; the second, commercially known as maloran, is selectively used for carrots, peas, potatoes, soy sprouts, and sunflowers. Considering the widespread use of herbicides and, more generally, pesticides, it is important to clarify their involvement on human health, one of them concerning the possible direct or indirect effect on the genome of exposed populations. Here, we show that these herbicides are endowed by mutagenic properties, as demonstrated by an increased number of chromosomal aberrations (CAs) in two exposed Chinese hamster cell lines derived from ovary and epithelial liver, respectively. This was also confirmed by sister chromatid exchange (SCE) and micronucleus (MN) assays. Our present and previously obtained data clearly indicate that phenylurea herbicides must be used with great caution, especially for agricultural workers who use large amounts of herbicides during their work, and particular attention should be given to residues of these herbicides and their involvement in environmental pollution.     

Assessment of compost quality for its environmentally safe use by means of an ecotoxicological test on a soil organism

A research project was carried out to evaluate toxicological effects of compost addition to agricultural soil using the earthworm Eisenia foetida (Annellida) as a representative organism of the soil fauna. Moreover, the correlation between compost biochemical stabilization and toxicity at different phases of the composting process was assessed. Samples were collected from three composting plants at three different maturation levels (beginning of the composting process, intermediate compost after bio-oxidation, and mature refined compost). Two tests were performed: a standard chronic solid-phase test and an acute solid-phase test (developed originally by the authors). In the first test, the measured end-points were mortality, growth and reproduction; while in the second test earthworms’ behavior was evaluated. The chosen compost concentrations in soil ranged from 2.5 to 100 %, with the aim of obtaining the toxicological parameters (LC50) and to mimic real agricultural dosages for the lower concentrations. Results indicated an increase in compost toxicity with greater compost concentrations; in particular, agricultural compost dosage below 10 % showed no toxicity. Moreover, toxicity did not decrease during composting; intermediate compost showed the highest LC50 values. As a consequence, no correlation was ascertained between the results of ecotoxicological analysis and waste biochemical stability parameters during the composting process.